Minot Floods Reviewed, 1904-1969
City Hit Twice by Monsters
Twice in this century - in 1904 and this year - flood spreading over the Mouse River Valley has swamped a large part of residential Minot, interfering with public services and requiring wholesale evacuation.
The flood of 1904 is the monster of Mouse history as far as water volume is concerned. Nineteen sixty-nine goes into the books as the worst disaster in terms of people affected and damage to property.
Once, before Minot existed, there was a flood, dated by pioneers as in 1881, when by evidence to which first settlers attested, the river may have gone three feet higher than in 1904. If that is true, this section of the valley has had three swamping floods in less that 90 years.
At least 10 other times in the 20th century spring runoff in the Mouse has caused flooding in Minot, of less than swamping proportions.
Of them all, six floods have produced crest flows through Minot exceeding 3,000 cubic feet per second, rising far above the natural banks of the river. These banks, with permanent diking that exists, today will accommodate flows from 2,000 to 2,300 second feet (depending on channel and flow conditions) without extensive inundation.
Engineers have estimated the peak flow of 1904 at 12,000 cubic feet per second.
Preliminary estimate has placed the 1969 peak at only 6,300 second feet. Yet because the lowlands now are almost completely occupied and built up (with many emergency dikes constructed this year) the 1969 water had less valley space to pass through. Consequently, water rose very high.
Flows may not be as good an index of damage as gauge height. Before there was a much diking, engineers used to say that the Mouse at Minot would begin going out of its banks at 16 feet. The peak stage of 1904 was found to have been 21.9 feet above the zero of a staff gauge near the Great Northern roundhouse. Peak stage of 1969 was measured at 20.44 feet at the USGS Gauging Station west of the city.
At the time of the 1904 flood, Minot had a population of 1,200, and the Minot Daily Optic reported that several hundred had to leave home.
This year with a population of 35,000, Minot saw more than 11,000 of its people evacuated from their houses or apartments.
Mouse floods at Minot do their damage not so much because of high crests as because high crests remain for weeks. Low-water slope of the river at Minot is about six inches per mile. With a great volume of flood water to be moved by gravity flow through a valley of low fall, it takes a long time for the water to pass.
A fair-sized flood occurred in 1916, when water rose to 19.05 feet on the downtown gauge, and spring run-off totaled 180,000 acre feet. This is rated as one of Minots most serious floods.
The flood ranking third in magnitude in Minots history is that of 1927. The city that year put more than a thousand men to work night and day to build up levees at a cost which exceeded $50,000. Several areas of the city were flooded despite this effort. Losses to property and losses of business in Minot that year are considered to have been greater than in all previous floods combined.
In 1927 the downtown gauge height was 20.17 feet. The estimated peak flow was 3,770 cubic feet per second. Total annual discharge of water through the Mouse that year is estimated to have been 319,840 acre feet, the largest since the 678,000 feet if annual water volume in 1904.
These annual discharge figures for two of the largest floods prior to 1969 compare with a 64- year average annual discharge of 97,010 acre feet.
There was not much thought or study of flood control possibilities at Minot until the latter half of the 1920s, as a result of a series of damaging floods in that decade.
Flood years have had a way of coming in bunches. In the 1920s there were four years of damaging high water. They were 1923, 1925, 1927 and 1928. In three of these years downtown gauge height exceeded 19 feet. This was a period when the city was building up, making many improvements, and when the amount of property subject to flooding was increasing.
In both 1923 and 1925 the peak flow through Minot is recorded at 3,450 cubic feet per second or thereabouts.
As a result of the experience of the 1920s a number of studies that had bearing on the Minot flood problem were undertaken by state and federal agencies. The initial study authorized by Congress was in 1929.
Most notable of the studies of this period is one on which a report was made in 1927 by R. E. Kennedy, then North Dakota state engineer. It proposed construction of an artificial flood channel through Minot 200 feet wide at the bottom and 12 feet deep, running the length of eight miles (half of the mileage in the city). It was estimated by Kennedy that such a channel would carry the flow of all but the monster floods. Price tag of the project was estimated at $1,200,000. Most of the cost would have been borne by assessments against property subject to damage by the city as a whole.
Following the Kennedy report, a St. Paul consulting engineer, L. P. Wolff, presented in 1928 a modification of Kennedys plan. Where Kennedy had recommended the chain-of-lakes route through north Minot for flood channel, Wolff proposed a route closer to that of the existing river channel. He suggested that the flood channel be designed to carry a flood the size of the 1904 flood with quite a margin of safety. His design would have carried a flow of 18,000 cubic feet per second or more. The estimated cost was a little less than Kennedys $1,200,000 figure.
Meanwhile a Ward County flood control board had been organized, with a view toward putting one of the artificial channel projects fell into effect. The proposal of the commission met defeat. It developed opposition on account of high costs as a viewed by residents of a city then struggling to provide itself with the public services normally regarded as essential.
Money, or the lack of it, was the big obstacle. The project produced disagreement and consequently no action on any plan for major surgery to prevent floods in Minot. The report which the Army Engineers presented to Congress in 1930 was a fact-finding report. It took cognizance of the money problem. It noted conflicting views in Minot, and said, Even if an agreement could be reached, it is doubtful that the City of Minot would be financially able to carry out an adequate plan.
A side result of this investigation was that the U.S. Geological Survey in 1931 installed a number of river-stage recording gauges in the Mouse.
With the 1930s came a long dry period. Nature did not force, or even nudge, Minot, or the various levels of government, to deal with the long-term problem.
The 1930s, however, brought an unexpected development. The U.S. Bureau of Biological Survey (which became the U.S. Fish and Wildlife Service) established two large waterfowl refuges on the Mouse, one above and one below Minot. Land for the project was acquired in the regions worst drouth years on the premise it was sub marginal.
A feature of this development was the construction 52 river miles above Minot of Lake Darling Dam capable of impounding 112,000 acre feet of water. Lake Darling reservoir was created in 1935 primarily to supply waterfowl marshes of two national refuges. The project gained support in Minot on the basis of its prime objective, but also because of a showing that the dam would reduce water damage in Minot in most flood years.
Not until 1943 was enough runoff produced in the Mouse watershed in Saskatchewan and North Dakota to push water over the Lake Darling spillway. That year water rose to 101.75 feet on the Northern States Power Company gauge in the city. It reached a maximum flow here of 2,480 cubic feet per second. April and May run-off through Minot totaled 175,400 acre feet. There was some minor inundation in the city, backup in sewers, and a considerable amount of travail. Old levees were raised. The city had to wait several weeks for the high water to go down.
Agreement was general that in its first year of spill-over Lake Darling Reservoir proved it could take the peak off of what, without it, would have been a more damaging flood in Minot.
The following year a veteran consulting engineer from Minneapolis, Adolph Meyer, gave Minoters assurance that Lake Darling Dam was sound, and that it would give Minot considerable protection in most years. He warned that Lake Darling could not be expected to provide flood control in such years as 1904 was.
A few years passed, and another series of flood years came close together. They were 1948, 1949 and 1951.
These were in the category of lesser floods, so far as Minot was concerned, but in 1949 there was a tremendous amount of high water in lower stretches of the river below Minot.
In 1948 peak flow at Minot was 2,700 cubic feet per second on May 8, and it caused considerable flooding. In downtown Minot the peak stage was 102.95 feet on the NSP gauge. Somebody calculated that this was four feet lower than the 1904 crest.
The flood of 1948 drove some families from their homes in Minot, flooded many basements, and caused a large amount of inconvenience. Basement flooding became extensive when a trunk sewer broke at the river crossing.
In 1949 the Mouse rose to 102.0 feet on the NSP gauge at Minot on April 6, and again there was overflow and inconvenience. Velva had a worse scare, with more than a hundred basements flooded. The large volume of water in the downstream stretches is indicated in the fact that a peak flow 5,200 cubic feet per second was recorded at Westhope in late April. The peak at Mnot, however, was only 2,250 second feet, but it occurred under conditions when even that flow was too much for the channel.
Lake Darling Dam had water running over its spillway in 1948, but in 1949 the reservoir became full without overflowing. Water, of course, was released through the gates in large amounts both years.
The flood of 1951 was another which sent water over the spillway of the dam. There was a long period of very high water in Minot, extending from early April to the latter part of June, for heavy June rains kept the water high until late. The peak flow at Minot was only 2,280 cubic feet per second, but the April-May runoff amounted to 181,400 acre feet.
The high-water year of 1955 was comparable to 1951 in peak flow at Minot and exceeded 1951 in April-May run-off.
In all these years Lake Darling Reservoir had reduced peak run-off at Minot to a point where Minot probably suffered less than the downstream farmers and ranchers.
Probably this modicum of protection made many Minoters feel complacent. As the city began to expand in residential building during the 1950s and the 1960s, many supposed that the flood hazard was something diking could control.
Encouragement in this belief came not only from less than ravaging behavior of the river, but from knowledge that the Canadians were building dams in the upper reaches of the watershed, holding back considerable runoff. There were those who said it was probable there would never be another 1904.
Not everyone was lulled, however. As early as 1950 (while the original Missouri-Souris irrigation project was under study) a move was initiated for investigation of Mouse flood control by the Corps of Engineers. In 1955 congressional committees asked for a review of the problem.
The city government and the Minot Chamber of Commerce began pressing for control measures in 1960. There was increased clamor for action to protect the city of Minot after a disastrous summer flash-flood, pouring in from a coulee, hit Velva in 1962. Meanwhile the Corps of Engineers was continuing its review, and was working on recommendations for a plan. The first proposals were presented at hearings held in Minot in 1965 and 1966. Alternative and additional protection phases of an over-all project were under consideration in 1967 and 1968, with final decisions yet to be made at the time the 1969 flood came.